IMR 7383 in 338win

[Lefty7mmstw]

Well, the cheapskate in me got the better of me earlier in the year and I sprung for a couple of kegs of IMR 7383 mil. surp. lot 81000 from Bartlett's. I also ordered 500 of the 185gr. over-run 338 bullets Midway had a few months back.
Well, after pouring over a lot of the info online I had myself questioning why on God's green Earth I had bothered to play with this odd duck of a powder. I surmised that my #1 in 338win mag. could handle about anything that powder could throw at it so I'd work up a load in that rifle first.
I ran the load from 62 gr 7383 to 67 gr 7383 and landed on 66grains as a sub moa load with almost zero unburned powder and good looking brass; normal looking primers, etc. also.
I figure I'm in for around $32 a hundred for the loaded ammo as long as my brass holds out. Nice cheap short/ mid range trigger time.
Next up is putting a load together for the 30-06 to save on 4350... I'll probably use up a peanut butter jar full of rem 165 grain pills I've had since high school.
It has been said you load the same volume of 7383 as you do IMR 4831, but the powder's density is low enough that the charge weight is 15% less. In the 338 win mag it seems to follow 4895 or 4320.

 

[fmuguira]

Thx for sharing your results. 3 of us ordered 7# kegs each to supplement our shooting and hoping some decent loads can be found to get us through this powder and primer debacle.

Figure that roughly 15 percent less than Imr4831 load data should be a good place to start. Maybe a couple grs under that calculated charge to start.

If others have history with this powder please do share !!

 

[Lefty7mmstw]

I'm up to around 40 rounds fired now with the 185gr bullet/ 66gr. 7383, wlrm 338win load now and it seems really steady. I haven't even bothered to chronograph it as it's a paper punching load to me. I may eventually run it past the Labradar my Pops has to check uniformity if I decide to hunt it.

 

[fmuguira]

Sounds good. I ll be interested to see what velocities are. I m thinking in the 'safe range' that 7383 is going to be off 150-200 fps vs other powders.

 

[Lefty7mmstw]

Well, the labradar was clocking the 185gr/ 66gr 7383 load in the 2630-2660fps range... I had expected more like 2800 fps, but oh, well. It's terribly cheap shooting and I suppose I could work up the load a touch and hit the 2800fps+ mark. I'll run my 225's with rl19 if I want full power stuff I guess though. For 100-200 yard trigger time 7383 is just fine.

 

[fmuguira]

Definitely gets you behind your rifle for less $$ ….. !

 

[Lefty7mmstw]

Definitely gets you behind your rifle for less $$ ….. !

under $40 a hundred

 

[Lefty7mmstw]

@fmuguira , any luck with 7383 so far yourself? I've been busy with a few other things lately, so I haven't worked up 30-06 stuff yet.

 

[fmuguira]

Friend has used it with good results and I was with him during load work.

Cartridge was 22 Creedmoor which is overbore. Typically runs R23 in it at 41-42 grains with 88 Eldm at 3200 -3250 fps. Long story short was 37 grs of 7383 gave just under 3000 fps and shot sub moa groups at 300 yds. Going up to 38-39 grains and groups opened way up. Pressure became present and erratic.

In this particular work up 7383 did pretty much what some folks said regarding pressure spikes and that it needs to be run at lower velocity/pressure. I had to convince my friend to "back off" as he thought it should give 3100-3200 fps since it's bulky and been compared to imr4831. My reasoning is the powder was designed for lower pressure from some research I d done and thus it became volatile, erratic or whatever word you d call it when pushed.

So overall with that 22 CM cartridge would call it a win. My opinion/thought is that it would likely perform similar in many other cartridges as long as a person loads it below normally max velocity/pressure for whatever cartridge you re working with. Advice….? Start low, it ll be dirty, gradually and carefully work up. Once it's burning clean in bore and you ve found accuracy STOP there. Don't try to hot rod it IMO!

Good Luck and please do share your findings and cartridge uses.

 

[Lefty7mmstw]

My opinion/thought is that it would likely perform similar in many other cartridges as long as a person loads it below normally max velocity/pressure for whatever cartridge you re working with. Advice….? Start low, it ll be dirty, gradually and carefully work up. Once it's burning clean in bore and you ve found accuracy STOP there. Don't try to hot rod it IMO!

Good Luck and please do share your findings and cartridge uses.

my thoughts exactly... you really can't push this stuff much over 50 Kpsi without it getting squirrely.
I'm wondering if my 338 would benefit from a heavier pill on the stuff for better uniformity/ energy generation, but she's shooting alright with the 185's and 7383.

 

[fmuguira]

If you re happy with then run it!!